"I always enjoyed tennis and relished the game away from tournaments too but in the last few months, all the talk about making history has brought too much pressure.

“It doesn’t mean I no longer want to contribute to the sport but I also don’t want to keep on playing just for the sake of winning titles.”

Djokovic, who steamrolled to Australian and French Open titles in the first half of the season, has suffered a dramatic loss of form since and pulled out of next week’s China Open with an elbow injury.

He lost to American Sam Querrey in the Wimbledon third round before he was knocked out in the opening round of the Olympic Games by Argentine Juan Martin del Potro.

Djokovic was unstoppable in 2015 when we won three out of four major titles and this year he finally completed a career slam after clinching his maiden French Open title by beating Briton Andy Murray in the final.

He pointed out several times after his Wimbledon and Olympic disappointments that the effort had drained him mentally and physically, raising question marks over his ability to equal Swiss maestro Roger Federer’s career tally of 17 grand slams.

Appearing to enjoy a light workout in the morning sun at a hardcourt complex overlooking the banks of Belgrade’s Sava river, Djokovic stressed that he was still keen to add more titles to his bulging trophy cabinet.

“If the wins and titles come I will embrace them with both arms,” he said.

“I am on an active vacation now and the Shanghai Masters is the next tournament.

“It’s a micro injury I am dealing with but its nature is such that it could develop into a long-term issue. I am close to being fully fit but the injury is still affecting my serve.”